Many pest control agents have been discovered to date. However, still novel pesticides are desired today owing to, for example, the resistant problem to pesticides and to concerns such as the persistence of the pesticide effects and safety at the time of use.
In paddy rice cultivation in East Asia and Southeast Asia in particular, as indicated in Non-Patent Document 1, damage by planthoppers which have developed chemical resistance to major insecticides, including neonicotinoids such as imidacloprid and phenylpyrazole pesticides such as fipronil has emerged. As a result, specific agents for planthoppers that have developed resistance are awaited.
With regard to heterocycle-containing amine derivatives, Patent Document 1 describes monoalkylamine compounds having a cyano group on the nitrogen atom, and the insecticidal activity of such compounds on aphids. However, no specific disclosure is made concerning dialkylamine compounds, nor is anything mentioned about the control activity on pests other than aphids.
Patent Document 2 mentions amine derivatives which contain a 2,6-dichloro-4-pyridyl group and have a carboxyl group on the nitrogen atom, as well as the fungicidal activities and insecticidal activities thereof, but discloses no other heterocycles.
In Non-Patent Documents 2 and 3, amine derivatives which contain a 6-chloro-3-pyridyl group and have an acetyl group on the nitrogen atom are disclosed as metabolites or reaction intermediates, but no mention is made of their pest control activities. Non-Patent Document 4 discloses amine derivatives which contain a 6-chloro-3-pyridyl group and have on the nitrogen atom a N-methylcarbamoyl group or a N-formylcarbamoyl group, but makes no mention of the pest control activities thereof.
Patent Document 3 discloses a plurality of compounds having ring structures similar to those of compounds of formula (Ie), but these are intended for use as herbicides; no mention is made of pest control.
Patent Document 4 discloses the structural formula of N-[1-((6-chloropyridin-3-yl)methyl)pyridin-2(1H)-ylidene]-2,2,2-trifluoroacetamide (Table 1, Compound No. 3 in Patent Document 4), but discloses nothing whatsoever concerning the method of preparation. Nor is this compound included in the lists of compounds for which pest control activities were observed (Tables 2 and 3 in Patent Document 4).
Patent Document 5 discloses the structural formula of N-[1-((6-chloropyridin-3-yl)methyl)pyridin-2(1H)-ylidene]-2,2,2-trifluoroacetamide (Table 7, Example No. 12 in Patent Document 5), but discloses nothing whatsoever concerning the method of preparation. Nor is this compound mentioned in the examples of compounds having pest control activities which are described in the working examples.
Non-Patent Document 5 discloses a plurality of compounds having ring structures similar to the compounds of subsequently mentioned formula (Ie), but these are merely disclosed as synthesis intermediates.
Patent Document 6 discloses a plurality of compounds having rings structures similar to the compounds of formula (Ie), but no mention or suggestion is made concerning compounds having a trifluoroacetic acid imino structure.